If you are running into memory issues such as below, there could be several causes but one of the causes is excessive parallelism and exhaustion of PGA memory. “ORA-01034: ORACLE not available / ORA-27102: out of memory / Linux-x86_64 Error: 12: Cannot allocate” Please read on to find out how to resolve this. There are … Continue reading Oracle – Parallel To PGA (P2P) & Serial To SGA (S2S) – Caching Differences And When Parallelism Is Not The Panacea For Performance!
What is a Semaphore? Instead of a clinical illustration of exclusive row lock and exclusive table lock usage in Oracle, here we will try to use them to highlight a higher level concept – Implement a semaphore mechanism. Wikipedia defines semaphore as below: In computer science, a semaphore is a variable or abstract data type … Continue reading Oracle – PL/SQL – Using ROW/TABLE Locks To Implement Application/Job Semaphore To Handle Race Conditions
Why is the APPEND hint so great? In a prior post, we extolled the virtues of the APPEND hint (AKA Direct Path Insert). It is a great option to use • UNDO usage is negligible. It is only generated for index maintenance and meta data changes. The keyword is index maintenance – indexes generate UNDO. … Continue reading Oracle – Is my APPEND Hint Being Ignored? How To Find Out?
Why asynchronous processing? If it takes a man 10 hours to do something, technically, it would take just one hour if 10 men did it. Right? Not quite, but it is somewhat true in the analogous computing world if resources are hardly maxed out when 10 threads are at work. It is more true when … Continue reading Invoke-Async – Asynchronous parallel processing for any workload in PowerShell